In the writers' first draft script of "Dear Doctor", Phlox revealed that his training had been at a research hospital on Denobula. In the episode's final draft script, it was established that his first assignment after medical training was at a mining compound in the rainforests of Pree'nos. There, although his fellow Denobulans tried to make the facility as similar as possible to Denobula, Phlox became fascinated by other aspects of the locale. "I found myself drawn outside the walls," he recalled, in a scripted voiceover, "to the camps of the Pree' themselves [....] I couldn't help thinking, why come all that way just to ignore the new world around you?"

Not long after Phlox became a physician circa 2115, there was an explosion in a cargo ship orbiting Denobula Triaxa. Phlox was part of the first medical team to arrive at the scene, where they discovered seventeen bodies on the bridge alone. That was the first time Phlox had seen that many dead people in one place before. (ENT: "Fight or Flight", "Damage") Phlox was once nearly overwhelmed with fifty patients in a refugee camp while serving on Matalas. (ENT: "Dear Doctor") Phlox also once served as a medic in the Denobulan Infantry. While in the infantry, he learned that battlefields are unpredictable places, even under a flag of truce. (ENT: "Cease Fire") During his first forty years of service as a doctor, he twice had to perform actions that he considered unethical. (ENT: "Damage")

In voiceover dialogue that was in the final draft script of "Dear Doctor" though not in that installment's final version, Phlox reckoned that his experience on Pree'nos, when he came to the opinion that he wanted to embrace other cultures, was what led him to Earth and, later, to other destinations in space.

In the writers' first draft script of "Dear Doctor", Phlox mentioned that he had never complained about the weather in San Francisco.

After displaying considerable expertise at sustaining the life of Klaang the Klingon courier, Phlox was brought on board Enterprise for the maiden voyage in April of 2151. Having lived on Earth for "many years", he concluded that while Humans were anatomically simplistic, they made up for their biological deficiencies with their charming optimism – and with their Chinese cuisine. During the mission Phlox determined that a captured Suliban had been genetically altered. (ENT: "Broken Bow")

In ultimately omitted dialogue from the final draft script of "The Aenar", Captain Archer speculated that Phlox would "love" to keep a few ice-bores from Andoria in his shipboard menagerie.

Early in the mission, the crew of Enterprise found a stranded ship with its entire crew complement dead. Phlox determined that the bodies had been drained of vital fluids. But the away team had to evacuate when a vessel approached. Dr. Phlox performed an autopsy on one of the dead bodies, and learned that it been drained for triglobulin, a fluid that could be used to create medicines. (ENT: "Fight or Flight")

His medical abilities were soon tested when the crew of Enterprise discovered an unexplored planet, and an away team from the starship became dangerously paranoid. Phlox was able to determine that pollen from the planet's indigenous plant life was affecting the team. Not only were they delusional, but the pollen was toxic. Phlox was able to produce an antidote and save the crewmembers. (ENT: "Strange New World")

Phlox later determined that Chief EngineerCharles "Trip" Tucker had become pregnant after an intimate encounter with a Xyrillian female. Dr. Phlox determined the growth in Tucker's body was an embryo forming in his ribs. Phlox also determined that the embryo was not Tucker's child, but that he was simply serving as a host. Phlox refused to perform any procedure to remove the embryo without learning more about the Xyrillian gestation process. (ENT: "Unexpected")

His medical expertise again proved useful when Enterprise encountered a lost Earth colony named Terra Nova. An asteroid impact had poisoned the planet's atmosphere in late 2078. Mistakenly believing that Earth had attacked the planet, the Novans were forced to seek refuge underground. Phlox later discovered that their water supply was poisoned by radiation. He gained the confidence of the Novans when he cured Nadet, an elder Novan, from lung cancer. This helped to build trust between the Novans and the mostly Human crew of Enterprise. (ENT: "Terra Nova")

Eventually, Phlox also became a counselor on the starship, who helped the other crew members with their problems. In June of 2151, Sub-CommanderT'Pol confided in him that she had been arranged to be married. The marriage was causing some concern for T'Pol, since she would have to leave Starfleet immediately and remain away for at least one (Vulcan) year. (ENT: "Breaking the Ice")

Later that year, the Enterprise answered a distress call from a cargo ship. The acting captain claimed that the call was a mistake and asked the Enterprise to leave. Dr. Phlox insisted on treating the injured captain. Phlox determined that Captain Jackson Keene required two or three days of treatment. (ENT: "Fortunate Son")

Phlox provided a clue to Malcolm Reed's favorite food for his surprise birthday party. He told Hoshi Sato, who was in charge of the arrangements, that Reed had been taking regular injections to counter an allergy to bromelain, a plant enzyme found in pineapple. Sato decided that the cake would be a pineapple one. (ENT: "Silent Enemy")

Phlox with Crewman Cutler in September of 2151

In September of 2151, Enterprise visited Valakis, a pre-warp civilization with two distinct humanoid races – the Valakians and the Menk. He became involved with a crewmember by the name of Elizabeth Cutler at this time. Phlox attempted to find a cure for a disease that was afflicting the Valakians, but not the Menk. Phlox learned that the Valakians were not suffering from a curable disease, but a genetic mutation that would eventually result in their extinction.

Despite the discovery of a cure, Phlox and Archer disagreed on whether to help the Valakians, as the doctor objected to interfering in their evolution and advised that nature should be allowed to take its course. Archer finally agreed and they transported to the planet's surface with medicine to ease the Valakians' symptoms. However, the officers refused to provide the Valakians with warp drive, which they wanted in order to seek other races that could help them. (ENT: "Dear Doctor")

The next month, Enterprise detected a Klingon Raptor-class, adrift in the atmosphere of a gas giant. Phlox determined that a Klingon rescued from the ship had been poisoned by a neural toxin. In fact, the entire crew of the Klingon ship was being poisoned. Phlox found a cure for the toxin and cured the Klingon crew. (ENT: "Sleeping Dogs")

Phlox performs cosmetic surgery on Reed

While investigating a rogue planet, Archer met a group of hunters called the Eska. They explained that they were hunting wraiths. After one of the hunters was injured by a wraith, Dr. Phlox tended to the injuries. A cell sample from the wraith found in the wound of the hunter helped Phlox to determine that the wraiths were sentient beings who were shapeshifters. The hunters used scanners to track the beings by their chemical signatures. Archer asked Dr. Phlox to come up with a way to mask the wraiths' chemical signatures, shielding them from the hunters' scans. Phlox was able to do so, and the hunters left the planet. (ENT: "Rogue Planet")

Phlox cosmetically transformed Reed into a Suliban so he could infiltrate a prison to rescue Archer and Mayweather. (ENT: "Detained")

In 2152, during the second year of Enterprise's voyage, Archer and several other crew members were attacked by an organism that entwined them in its tentacles. Dr. Phlox analyzed a piece of the organism and determined that the tendril appeared to be capable of surviving independently, that it possessed a sophisticated nervous system, and was a sentient being. Phlox tried to free them by using EM radiation, but the organism was integrating the crewmembers' nervous systems into its own and they could end up killing the crew. The crew members were finally released when Sato managed to communicate with the organism and it was returned to its home planet. (ENT: "Vox Sola")

Crewman Cutler and T'Pol have to interrupt Phlox's hibernation in his quarters

Phlox also saved Ensign Travis Mayweather's life after the helmsman was injured in a rock-climbing incident. The Denobulan had to be woken during his annual six-day hibernation sleep, and acted somewhat irrationally as a result. (ENT: "Two Days and Two Nights")

After being damaged by a Romulanminefield in April of 2152, Enterprise stopped at an automated repair station. Ensign Mayweather was apparently killed on the space station and his inanimate body was returned to the starship. However, Phlox determined that the body was actually a duplicate of the helmsman due to the fact that various microorganisms in his bloodstream – part of a vaccine Phlox had recently given the crew – were all dead; if Mayweather had died under the circumstances that had apparently killed him, the organisms should have been fine. In reality, the station was using Mayweather's brain as a computer processor. (ENT: "Dead Stop")

During a visit to a small miningcolony, Archer negotiated an agreement to obtain deuterium in exchange for medical supplies and assistance in repairing the colony's extraction pumps. Phlox gave the medical supplies to E'Lis, a doctor in the colony. He offered her an osmotic eel, which was used to cauterize wounds. She joked that she wouldn't know what to feed it. (ENT: "Marauders")

While working on a Suliban cloaked craft, particle radiation caused Tucker's arm to become invisible. They were going to use the ship in the rescue attempt of Archer and Reed who were going to be executed on a pre-warp planet. Phlox informed Tucker that it would eventually materialize on its own. Tucker told Phlox he couldn't work this way. Phlox gave him a glove to put on. (ENT: "The Communicator")

After an encounter with a black hole whose radiation had affected the crew by causing obsessive behavior, Phlox wanted to perform major surgery on Mayweather to cure him of a simple headache. Phlox seemed to be more sensitive to the effect than the Human crew. T'Pol stormed into the sickbay to save Mayweather but Phlox threatened her with a surgical knife, only to be neutralized by T'Pol with a Vulcan nerve pinch on the last minute saving Mayweather's life. The effects dissipated after the starship passed the black hole. (ENT: "Singularity")

When the Enterprise crew discovered a futuristic vessel with a dead humanoid in it, Phlox discovered that the corpse had genetic material belonging to several other species, including Vulcans. He believed that the individual seemed to be the result of several generations of interspecies breeding. Phlox also visited Archer in a Klingon prison to examine him. He pretended that Archer might have a contagious disease so that the guard would leave them alone. He then informed Archer that a rescue attempt was planned. (ENT: "Future Tense", "Judgment")

Phlox was attacked by an alien using Sato's body as he attempted to find a cure for the alien possession. The aliens had attempted to enter his body, but they could not survive in his body due to his biological make up. Phlox was able to release carbon dioxide into Enterprise's living quarters, rendering the affected crewmembers unconscious, and forcing the aliens to leave the crew's bodies as they weren't able to survive. He helped Tucker determine that the cogenitor of the Vissians was an intelligent being and had the same mental capabilities as the Vissians. While going through decontamination with T'Pol to rid themselves of a virus, T'Pol became very amorous toward Phlox as the virus had activated her mating cycle ahead of schedule and was causing her to undergo pon farr. Phlox tried to find a treatment, but T'Pol knocked Phlox out and escaped. Phlox found a cure for her, before the virus killed her. T'Pol was embarrassed, but Phlox promised not to mention what happened to anyone. (ENT: "The Crossing", "Cogenitor", "Bounty")

Phlox undergoes his painful cure

It was shortly after these events that Enterprise was sent after a group of cybernetic beings that had recently attacked a research team in the Arctic. (Although unknown, these were some of the Borg who had attempted to prevent Earth's First Contact.) During this attack, Phlox was infected with Borg nanoprobes, but his immune system managed to keep them under control until he was able to destroy the nanobots by subjecting himself to a potentially lethal radiation dose. During this time, he was briefly linked to the Borg hive mind. He described this as being connected with the rest of the aliens, as if he was part of a collective consciousness. Phlox also said that they were trying to send some sort of message. The message was coordinates, telling their homeworld how to find Earth. (ENT: "Regeneration")

Phlox learned that T'Pol had been afflicted with Pa'nar Syndrome, a deadly brain disorder, after she had been forced to participate in a mind meld against her will. Phlox attended a medical conference on Dekendi III with a group of Vulcan doctors, but his efforts to obtain information concerning the disease were rebuffed. The Vulcans viewed the condition, and those who were affected by it, as outcasts. Phlox could not tell them that T'Pol had the disease, as the Vulcan High Command would demand that she return to her homeworld for punishment if they found out. T'Pol was left alone when one of the doctors confessed that he also performed mind melds.

During this incident, one of Phlox's wives, Feezal, visited him on Enterprise. She made advances towards Commander Tucker. Although the engineer informed Phlox of Feezal's implied sexual gestures, the doctor advised Tucker not to ignore the romantic overtures. (ENT: "Stigma")

During an evacuation mission, Phlox attempted to treat an Antaran named Hudak. The Antarans and Denobulans had been enemies for centuries, and Hudak consequently refused treatment. When Archer ordered Phlox to treat the Antaran, the Denobulan doctor replied by acknowledging his own responsibility to respect the wishes of his patients and still refused to treat Hudak. After several discussions with the patient (which were initially very difficult), Phlox was able to convince him that he was neither bigoted nor hated Antarans. The Antaran subsequently consented to treatment. (ENT: "The Breach")

In the final draft script of "The Breach", a scene description during one of the first conversations Phlox has with Hudak stated, "We've never seen Phlox lose his temper before, if we even realized that he had one."

In April 2153, an unidentified alien probe attacked Earth before self-destructing. Captain Archer was shocked to learn that the probe had been built by an alien race called the Xindi that was building an extremely powerful weapon designed to annihilate Earth. Starfleet permitted Archer to command Enterprise on a mission to find, and destroy, the weapon in the perilous Delphic Expanse.

T'Pol and Phlox wonder how best they can respond to the attack on Humanity

Although the crew were asked to choose whether to participate in the mission or to leave the ship, Phlox found the decision, to stay, easy to make. He based his choice on his strong loyalty to Archer and his realization that his medical skills would be needed more than ever. (ENT: "The Expanse")

Shortly after the starship entered the Delphic Expanse, Phlox became concerned about Commander Tucker, who had been experiencing trouble sleeping due to stress from his sister's death during the first Xindi attack. The doctor asked T'Pol to administer Vulcan neuro-pressure to Tucker, and she eventually complied.

First contact with the Xindi was made on a trellium mining planet, where a Xindi-Primate named Kessick worked. Members of Enterprise's crew attempted to help the Xindi escape, but Kessick was killed in the attempt. Before he died, he told Phlox the coordinates for the Xindi homeworld. However, the crew unfortunately found that the planet had been destroyed in the 2030s. (ENT: "The Xindi")

As the mission continued, the crew of Enterprise discovered a planet where all life had become extinct. An away team sent from Enterprise began to develop alien characteristics, due to a virus created by the planet's inhabitants in a last attempt to repopulate their homeworld. Although Phlox found a cure, he preserved the virus to save with the remains of the species. (ENT: "Extinction")

He later tried to examine a Xindi weapon that was organic. The weapon was a booby-trap and almost caused an explosion. He was able to determine that using delta radiation would render the weapon harmless. (ENT: "The Shipment")

Phlox treated Bethany, a Human inhabiting a planet similar to the Old West of Earth. The original Humans were abducted by a race called the Skagarans. They revolted and overthrew the Skagarans, making them second-class citizens without rights. She was wounded in a gun fight and beamed aboard Enterprise, where Phlox took the bullet out of her and also discovered that she was part Skagaran. (ENT: "North Star")

In a test of his medical ethics, Phlox created a clone of Tucker in order to save the original Human, who had been injured in an accident. The clone, named Sim, could live for only fifteen days, but its organs could be used to heal Tucker. Sim discovered an enzyme that could possibly allow him to survive longer than fifteen days. Phlox examined the enzyme and verified the possibility, but the treatment was dismissed as it would take too long to confirm whether it had worked, leaving them with no opportunity to save Trip if the procedure failed. Because Phlox refused to kill another sentient being, it seemed likely that Tucker would die. Eventually, Sim gave up his life so Tucker could live and help to complete the Xindi mission, his last words being to assure Phlox that Phlox had been a good "father" to him in his brief "childhood". (ENT: "Similitude")

In an ultimately unused line of dialogue from the final draft script of "Similitude", Phlox advised Archer, prior to Sim being developed, that the creation of the mimetic simbiot should be begun "the sooner the better."

Unlike most Denobulans, Phlox did not usually hallucinate to relieve stress. During the search for the Xindi weapon, he admitted to having frequently envied those who were able to do so, as he had a habit of keeping "too much bottled up inside". (ENT: "Exile")

Phlox helped Archer neutralize the Triannons who had hijacked the Enterprise. After he distracted his guard by releasing his bat and claiming it was poisonous, he formulated an airborne agent that neutralized the Triannons' organic explosives, allowing Archer and the MACOs to retake the ship. (ENT: "Chosen Realm")

Degra, the Xindi who designed the weapon that would destroy Earth, was captured by the Enterprise. In order to trick him into revealing the location of the weapon, Phlox found out that it was possible to erase the Xindi's most recent memories. After Degra revealed the location, Archer had Phlox wipe Degra's memory again, so he would not remember giving the location of the weapon or being on the Enterprise. (ENT: "Stratagem")

Enterprise encountered a spatial distortion. They discovered a small craft in the anomaly piloted by an alien who was unconscious. Phlox examined the alien and determined that the alien was suffering from rapid cellular degeneration. The alien was a member of the sphere builders who were behind the plot to have the Xindi destroy Earth. The alien asked Phlox if he was going to die and Phlox told him he was doing everything he could to help him. Later the alien attacked Phlox and knocked him out in an unsuccessful escape attempt.

Phlox also informed T'Pol that Amanda Cole was having headaches due to Tucker's improper use of Vulcan neural pressure techniques. He asked T'pol to talk to Tucker about it, and if she could see Cole and help her with her headaches. It was clear that T'Pol was not pleased and was jealous. (ENT: "Harbinger")

Phlox enjoys a bowl of popcorn on a solitary "movie night" while piloting Enterprise alone for four days in 2153

The following month, Phlox was left to run Enterprise by himself due to a trans-dimensional disturbance that could be fatal to the crew. His Denobulan physiology made him immune to the effects of the disturbance. He placed each crewmember in a comatose state and watched over the ship. However, the solitude of the situation caused him to experience hallucinations. T'Pol joined him because Vulcans were immune to the disturbance's effects as well. Phlox believed he saw a Xindi-Insectoid on the ship and kept hearing strange noises. He also discovered that Enterprise wouldn't clear the disturbance before the crew awoke. Phlox, with T'Pol's help, took the ship to warp and saved the crew. As he awoke the crew, Phlox discovered that T'Pol had been in stasis the whole time and that she was one of his hallucinations. (ENT: "Doctor's Orders")

Phlox actor John Billingsley had mixed feelings about his character being given more screen time than usual in "Doctor's Orders". "The good news is that I didn't have too many lines to learn," he commented, "the bad news is that it's working about 16 hours a day when you factor in the makeup time." Billingsley also thought he was less well equipped to portray Phlox in "Doctor's Orders" than in some other episodes, remarking, "For my tastes and for what I think I'm best utilised to do, the episodes that are more reflective, philosophical and meditative – that deal with issues such as cultural conflict – I think those are the things that I am probably best equipped to do." [1] Conversely, the depiction of Phlox in "Doctor's Orders" pleased series co-creator and Executive Producer Brannon Braga, who noted about Billingsley's performance in the outing, "He was wonderful." Braga also liked how Phlox's relationship with T'Pol is featured in "Doctor's Orders". (Star Trek: Communicator issue 151, p. 32)

The starship's mission in the Delphic Expanse came to a successful conclusion when the Xindi weapon was destroyed and the spheres eliminated. As Enterprise attempted to destroy the spheres, Phlox told the MACOs to compensate their weapon frequencies for trans-dimensional firing. This helped them to hold off the Sphere-Builders until the spheres could be destroyed.

Phlox was present at a ceremony held in Bay Stadium to celebrate Enterprise's return to Earth. He collected some equipment from Enterprise, before visiting a bar on Earth with other members of the starship's crew. When a xenophobic Human assaulted him there, Phlox expanded his face in an instinctive defensive posture. (ENT: "Home")

Phlox returned to Enterprise before it resumed its normal missions, taking a Dr. Arik Soong on board. Soong had created a group of Human Augments, some of whom had attacked and commandeered a Klingon Bird-of-Prey, and was brought on board Enterprise to help capture them. Phlox met Soong on the starship and criticized his attempt to redesign the Human species using genetics without responsibly learning from the Eugenics Wars. Soong later escaped with the Augments. (ENT: "Borderland")

When a young man named Udar was found by an away team from Enterprise and brought on board the ship, Phlox examined him. The doctor told Captain Archer that Udar was in good condition except from being dehydrated and suffering from malnutrition. Archer believed he was an Augment but Phlox corrected the captain that Udar was an anomaly whose DNA was similar but not identical to the Augments and had been born without their enhanced abilities.

Phlox later told Archer that Udar was ready to be released from sickbay. The captain gravely informed Phlox that his old friend, Doctor Jeremy Lucas, was at Cold Station 12, an outpost that the Augments were planning to capture as it contained the embryos of many unborn Augments. The Denobulan doctor was shocked to learn the news but appreciated Archer telling him. According to Phlox, Doctor Lucas had revealed he was being transferred in his last communique but had not revealed his next assignment.

Having spent a few months at Cold Station 12 himself, Phlox was familiar with the security protocols and technology there. He urged Captain Archer to include him in the away team to retake the station and Archer soon accepted.

When Enterprise arrived at the outpost, Soong and the Augments had taken the staff hostage. In order to steal the embryos, they required access codes from Dr. Lucas. He refused to give them the codes, even though they killed one of his associates. After capturing the away team from Enterprise, Malik, the leader of the Augments, threatened to kill Phlox unless Lucas complied which he ultimately did. (ENT: "Cold Station 12")

After returning from an away mission, Commander Tucker and Ensign Sato became ill. Phlox announced that they had an incurable silicon-based virus. With no known cure in the Denobulan medical database, he administered them with medicine to make them sleep and to ease their pain. When they suddenly awoke and aliens announced they had possessed the officers' bodies to experience Human feelings, Phlox was shocked. Before he could warn Archer, however, his memory was erased. The aliens were actually harmless and after experiencing Human sensation, they cured the infected crew members. (ENT: "Observer Effect")

Phlox's medical expertise came into play during the incident with the Romulan drone ship. After Shran's ship was destroyed by the drone ship, Phlox treated the survivors. He was unable to save Talas, Shran's second in command and his love interest, who had been shot by a Tellarite. Phlox helped construct a telepresence unit to interfere with the Romulans' navigation of the drone ship. He believed that it would be dangerous since the wearer might suffer neurolytic shock and brain damage. He monitored T'Pol who wore the interface. He treated her after she went into shock.

When Jhamel, an Aenar, tried to contact her brother Gareb, who was being used by the Romulans to pilot the drone vessel though a neural interface, she too suffered a seizure. Against Phlox's advice Jhamel tried again and was able to contact her brother and stop the attack against Enterprise. (ENT: "Babel One", "United", "The Aenar")

Klingons bringing Phlox to Qu'Vat Colony

In November of 2154, Phlox was approached by the Interspecies Medical Exchange and asked if he was interested in becoming their Director of Xenobiology. Shortly before he was captured by Rigelians working for the Klingon Empire, Ensign Sato revealed that Phlox often frequented a restaurant called "Madame Chang's". Following his kidnapping, the Denobulan was taken to Qu'Vat Colony, where, with the assistance of DoctorAntaak, Phlox was forced to help the Klingons develop a vaccine for a mutagenic virus. Phlox realized the Klingons were trying to create Augments. Antaak said the Klingon Augments looked Human, but their neural pathways began to degrade and they died in agony. One Augment had the Levodian flu, and his Augment genes modified the virus and it became airborne, resulting in the current plague.

After examining Phlox's research, Antaak believed the doctor had discovered a cure for the plague. Phlox and Antaak could cure the virus in its early stage. It would still change the Klingon's appearance and leave them with somewhat aggressive personalities – an effect that would remain for about a century or so – but not add any augment powers, such as enhanced strength and speed. Phlox was able to cure the plague, saving the Klingon race, but ending their experiments in augmentation. (ENT: "Affliction", "Divergence")

When Orion women boarded the Enterprise as part of a trade deal with the Orions, strange things started to happen on the ship. The men became aggressive and delusional, while the women suffered from headaches and listlessness. Phlox determined the women had exposed the ship to a very potent pheromone in an attempt to disturb the ship so that it can be captured by the Orions. T'Pol was not affected by the women and was able to direct the ship and defeat the Orions. (ENT: "Bound")

During the conference concerning the formation of a coalition of planets, a woman burst in and collapsed to the ground. Before she died, she pressed a vial containing Human hair into T'Pol's hand. Phlox examined the hair and stated that the DNA was part Human and part Vulcan. The DNA was Tucker's and T'Pol's. A baby had been cloned by a terrorist organization known as Terra Prime who was dedicated to driving all aliens off Earth. Although the organization's plot to destroy the coalition of planets was stopped, Tucker's and T'Pol's daughter, who they had named Elizabeth, was dying. Phlox determined that their DNA were not compatible. After the child died, Phlox discovered that there was a flaw in the cloning. He told Tucker that there was no medical reason why a Human and a Vulcan could not have a healthy child. (ENT: "Demons", "Terra Prime")

Phlox continued to serve aboard Enterprise, when the ship traveled back to Earth to be decommissioned prior to the signing of the Federation Charter. On the way there, Enterprise was diverted for one last mission to rescue Talla, daughter of the Andorian Shran, a former member of the Andorian Imperial Guard who was once an ally of Archer. Although the mission was a success, the ship was later boarded by the alien kidnappers and Commander Tucker was critically injured while trying to save Captain Archer's life. Phlox did everything he could do to save Tucker, but he ultimately died.

Phlox had three wives, each with three husbands, including Phlox, resulting in a total of 720 relationships, 42 of which had romantic possibilities. There were 31 children in his extended family, and he had five children of his own: three sons and two daughters. His poor singing of Denobulanlullabies made them cry. All his children left years before his assignment to Enterprise. His daughters were a surgeon and a biochemist. His oldest son was an artist, specifically a potter, and lived in the same town as his mother. He hadn't spoken to his two younger sons (one of whom was named Mettus) in several years, as they never saw eye-to-eye with Phlox. Mettus held archaic, anti-Antaran beliefs even though Phlox tried to instill in him the ideal to embrace other cultures. (ENT: "Storm Front", "A Night in Sickbay", "The Breach")

There was once a misconception that Phlox would have an affair with Trip Tucker. The actor who played the latter character, Connor Trinneer, mistakenly assumed that was going to happen when he visited the writers' offices and noticed a story note on a board that read, "Phlox/Trip/Trisexual", unaware it was actually a reference to the narrative for the episode "Cogenitor". (Beyond the Final Frontier, p. 380)

Phlox became one of Archer's most trusted advisers and on many occasions his counselor. He also frequently played devil's advocate for Archer. There were a few issues that they came into conflict over, but this only strengthened their friendship.

Early in the mission the Enterprise answered a distress call from a from a planet called Valakis whose population had two species, the Valakians, and the Menk. The Valakians were being killed due to an unknown epidemic. Phlox discovered that the illness was genetic. Archer wanted to know if a cure was possible. Phlox stated that he had a cure, but that it might not be ethical to administer it, because such a cure would interfere with nature. The Menk were on the verge of evolving to become the dominant species on the planet, which wouldn't happen as long as the Valakians were around. Archer believed that they had a moral obligation to provide a cure. Phlox argued the opposite and in the end convinced Archer that they had no right to play God. Phlox gained a new respect for Archer. (ENT: "Dear Doctor")

Later that year Phlox advised Archer on how to deal with a Klingon named Bu'kaH in order to persuade her to help with a rescue attempt. (ENT: "Sleeping Dogs")

Phlox endeared himself to Archer when he saved Archer's dog Porthos. This occurred during another diplomatic incident with the Kreetassans. Archer was angry and refused to try and settle the dispute even if it meant the Enterprise would not receive supplies it needed. Spending the night in sickbay, Phlox was able to get Archer to open up about a variety of issues including his attraction to T'Pol. Phlox cleverly discussed his extended family and cultural differences, pointing out that each species has different customs that must be respected, giving Archer a greater understanding of other cultures and persuaded him that he must apologize to the Kreetassans. (ENT: "A Night in Sickbay")

Phlox also accepted advice from Archer when an Antaran refused to be treated by Phlox. The Denobulans and Antaran were mortal enemies. Archer ordered Phlox to do so, but the doctor would not treat the Antaran without his consent. Archer convinced Phlox to set aside his preconceptions and attempt to persuade the Antaran to accept treatment. Phlox's attempts were successful and the Antaran gave his consent. (ENT: "The Breach")

Phlox and Archer continued their friendship for the rest of Enterprise's mission, depending on each other for not only friendship, but counseling.

Though Dr. Phlox was one of two aliens aboard Enterprise, he was able to socialize with the Enterprise crew, striking up friendships with many of the crew.

Phlox was also key in helping Hoshi Sato realize that she belonged on Enterprise. On a mission involving the Axanar, Phlox began to build a relationship with Sato. He also helped Sato to survive the mission when she panicked after aliens attacked Enterprise. He pointed out that she had to adapt to her new surroundings. (ENT: "Fight or Flight")

She and Phlox continued to confide in each other. They shared meals together, and he taught her Denobulan. They also discussed private issues. She tried to find out whether he had a lover back home and he would ask her advice about a crewmember named Cutler, who was sending him romantic signals. (ENT: "Dear Doctor")

When Phlox was infected with nanoprobes in 2153, Sato offered to keep him company in sickbay, as he had done the same for her "more times than I can count". Phlox politely refused, making sure that Sato would be safe if the nanoprobes took over him completely. (ENT: "Regeneration")

During a visit to the planet Valakis, Phlox had his first intimate encounter with a member of the starship's crew. Crewman Elizabeth Cutler, a female biologist assigned to Enterprise, became romantically interested in him. She helped him in his efforts to cure a disease that was afflicting the Valakians. Phlox was teaching her to be a part-time medic. Phlox asked her about her attraction to him. He said that he already had three current wives back home, which was perfectly normal for his culture. Taken aback, Cutler admitted her interest in him, but she didn't want to be wife number four, only a friend. Phlox and Cutler ultimately decided to simply continue their platonic friendship.

Phlox had another Human friend in regular correspondent Dr. Lucas, a colleague from the Interspecies Medical Exchange. Lucas was the first Human serving on Phlox's homeworld of Denobula. Lucas helped Phlox settle in when he came to Earth, and Phlox tried to help Lucas become accustomed to the Denobulan culture. He confided in Lucas about his relationships with the crew. This friendship came into play during the Augment Crisis. Malik, an Augment, attacked Cold Station 12 where Lucas was stationed after his duty on Denobula. The Enterprise tried to intervene and crewmembers were captured by the Augments. When they realized Lucas' connection to Phlox, they threatened to kill the Enterprise doctor with a deadly pathogen if Lucas didn't give up the access code so they could take the augment embryos. Fearing for his friend's life, Lucas disclosed the information. (ENT: "Dear Doctor", "Cold Station 12")

In an alternate timeline wherein Archer was infected by interspatial parasites from a spatial anomaly and consequently developed anterograde amnesia, Phlox was unable to remove the organisms, because they existed in a spatial domain outside the one inhabited by Phlox, Archer, and the others. After the Xindi destroyed Earth and most of mankind, Phlox did not accompany Enterprise to the Ceti Alpha system. Rather, he returned home to Denobula, where he spent a decade consulting with his planet's best neurosurgeons and quantum physicists on the best way to remove the parasites from Archer's brain. Having been told this could only be done with a subspace implosion which would kill Archer as well, Phlox set to work on creating a non-lethal way to treat the captain. When such a way was developed in 2165, he returned to Ceti Alpha V with this cure.

Phlox's arrival on Ceti Alpha V was featured in a short scene which was written into the final draft script of "Twilight" but is not in that episode's final edit. A scene description from the scripted scene described the 2165 version of Phlox thus; "He's a little older, and his hair a little longer, but he's the same old Phlox." The scene continued with Phlox saying to Archer, who had answered the door to him, "Greetings, Captain!" despite the fact Archer was no longer a captain.

Phlox thereafter treated Archer aboard Enterprise, as only a warp engine could produce the power necessary to destroy the parasites. After an initial treatment, Phlox and T'Pol made an astonishing discovery: the parasites eradicated so far had disappeared from Archer's brain in all scans from the day he was infected. If he could be fully cured, history could be changed, and Humanity and Earth could possibly be saved.

However, Phlox had been tailed to Ceti Alpha V by Yerdrin Lek, who gave the location of the Human colony to the Xindi. Knowing a fleet was on the way to finish off the Human race once and for all, Captain Tucker, needing all available power for weapons, ordered the treatment halted. After Xindi warships destroyed the bridge, Phlox and T'Pol brought Archer to Engineering, hoping to finish what they started. They arrived only to find that the chamber used in the treatment had been damaged beyond repair. However, Archer, now aware that curing him would mean he was never infected in the first place, recalled that a subspace impolsion could destroy the parasites, and the three set out to alter the warp core to cause one. Phlox and T'Pol remained to assist Archer in triggering the overload even when Archer gave them the chance to depart, reasoning that the Xindi would not be interested in them when Xindi's sole vendetta was with the Human race. Along with T'Pol, Phlox was killed once the Xindi boarded Enterprise, but Archer, with his dying breath, was able to cause the implosion, destroying the parasites and restoring the timeline. (ENT: "Twilight")

In a different timeline where Enterprise was stranded in 2037, Phlox had nine children with Corporal Amanda Cole. Many of the ship's crew were descendants of Phlox. Phlox also discovered a way to combine the Vulcan and Human genomes, allowing Tucker and T'Pol to mate and produce Lorian. In this timeline, Phlox had died by 2154. (ENT: "E²")

In the series bible for Star Trek: Enterprise, Phlox was described thus; "Full name is 'Phloxx-tunnai-oortann' but he goes by 'Phlox' for our benefit. Our most exotic character, the Doctor is an eccentric alien with an oblique sense of humor that no one quite understands. Because he speaks with an accent, and isn't familiar with Earth cultures, there are many humorous misunderstandings. Phlox thinks that humanity is fascinating – the complex sexual mores (his species reproduces asexually), social customs... oh my, what wonderful creatures! To say the Doctor has made himself 'at home' on the Enterprise is putting it mildly. He's filled Sickbay with all sorts of bizarre medical instruments, alien plants and spores, and stasis chambers filled with small, living creatures. He practices a brand of 'intergalactic medicine' the likes of which we've never seen. This makes the most routine visit to Sickbay an unexpected adventure."

In a character breakdown sheet that Paramount sent to talent agents while initially seeking an actor to play Phlox, the character was described thus; "Exotic alien. Medical officer. Appears to be in his 40s, but we're not certain of his real age. Phlox speaks with a slight alien accent and has an eccentric sense of humor that no one quite understands. He thinks that humanity is fascinating. The Doctor has filled Sickbay with all sorts of bizarre medical instruments, alien plants and spores, and stasis chambers with small, living creatures. He practices a brand of 'Intergalactic medicine' the likes of which we've never seen. This makes the most routine visit to Sickbay an unexpected adventure." [2]

In the script of ENT: "Broken Bow" (both the second draft and the revised final draft of the teleplay), Phlox was described as "an exotic-looking alien physician [...] [with a] slight, distinctive accent." [3]

The role of Phlox was conceived and cast before his species and homeworld were named. "We had one conversation in which we spoke in very general terms about the philosophical attitude of this guy, and we were totally simpatico," remembered John Billingsley. Unaware of what the character's future held, Billingsley, from then on, formulated some early thoughts of his own about Phlox and how he was regarded on his home planet. For instance, the actor thought of Phlox as "more party animal" than the others of his kind. Due to Phlox's cheerfulness, Billingsley regarded Phlox as the one character from his acting career which he based most on himself, the actor simultaneously recognizing this as somewhat odd. Though Billingsley didn't consider himself challenged by the creation of an entirely new alien, he did think it was challenging to try to determine why Phlox was the way he was, despite meanwhile loving that task. (Star Trek: The Magazine Volume 2, Issue 7, p. 28)

John Billingsley found some of his regular preparation for playing Phlox was grueling, due to the makeup required for the part. This was because its application meant he usually had to arrive two-and-a-half hours earlier than the production crew and, to have it removed, he needed to depart an hour after everyone else had already left. (Star Trek: Communicator issue 152, p. 26)

Hair stylist Michael Moore found that Phlox's hairstyle essentially fell together naturally, without investing much consideration or effort in it. "It just kind of happened," Moore laughed. "We had the front made, and we weren't sure what we wanted to do with it. We knew we wanted to use [John Billingsley's] own hair for the back. I put some curl in it and went with it. Rick [Berman] came down and looked at it and said, 'Good!'" In regards to how he changed the hairstyle in the series' third season, Moore concluded, "I made it more like a guy with longer hair, and he just combs it back." (Star Trek: Communicator issue 152, p. 31)

Early in the series run of Star Trek: Enterprise, Brannon Braga considered Phlox a challenge to depict. "I don't want our doctor to just become an amalgam of medical ethic stories," Braga admitted, shortly after ENT Season 1 began. "He's a really weird alien, a kind of Dian Fossey aboard the ship; he's among the primates. He's hopefully going to study humans and get out and about a little more. But the biggest danger with him, which we have avoided so far, is making him like Neelix. The impulse is to make him really cutesy and kind of wacky, and we don't want to do that." (Star Trek: The Magazine Volume 2, Issue 9, p. 22)

Phlox turned out to be an extremely popular character. "A lot of that comes from the way John Billingsley plays him," Brannon Braga noted. Braga believed that, for instance, Billingsley was such a good actor as to ensure Phlox was definitely considered a new character. "Any fears people had initially that he might be like Voyager's Neelix are long gone," Braga stated, following ENT Season 2. "We've really hit a home run with Phlox, in large part due to John." (Star Trek: Communicator issue 145, pp. 29-30)

In Beyond the Final Frontier, Mark Jones and Lance Parkin additionally expressed their own opinion of Phlox, remarking, "John Billingsley, like Robert Picardo and Brent Spiner before him, has taken what might have been a gimmicky character, Dr. Phlox, and made him very rounded and appealing." Jones and Parkin also conveyed pleasure at seeing Phlox be represented as having "hidden depths and secrets (but thankfully not sinister ones)." (Beyond the Final Frontier, pp. 357 & 364)